The medical and scientific worlds were quick to call Dr. Robert Lustig a crackpot when he first started telling the world that fructose was a poison. This month, a study by UCLA scientists vindicated the “fructose is poison” message. The paper was published in the journal EBioMedicine, which is about as reputable as journals come—it’s jointly published by The Lancet and Cell, two highly respected medical journals. And what it tells us is that not only is excess fructose a poison, it’s much worse than anyone ever imagined.

Fructose doesn’t just make us fat and diabetic, like Dr. Lustig tells us. It doesn’t just damage the liver. It actually causes genetic damage—in the brain.

This isn’t the first time UCLA has looked at fructose and the brainThis month’s study expands on a study UCLA researchers did back in 2012. Both studies found that rats given fructose-sweetened water did much more poorly on memory tasks. In 2012, they didn’t know why this happened, and speculated that fructose might change the way the brain responds to insulin. The new study shows something entirely different—and more frightening.

For this study, the researchers taught rats to navigate a maze. One group of rats was then given what would be, in a human, a liter bottle of soda’s worth of fructose each day for six weeks. Another group was given plain water. A third was given fructose and also fed a diet rich in the omega-3 fatty acid DHA. After six weeks, the rats were put into the maze again.

What happened then should make all of us sit up and take notice. The rats drinking fructose-laced water did only half as well as the rats who’d been drinking plain water. That might not sound like a big deal—after all, it was only rats in a maze. But change the scenario a bit and it’s a much different picture.

Say instead of rats in a maze, we’re talking about you driving your car through town, and without street signs to guide you. You drive to a friend’s house several times with your friend along to show you the way. Then you don’t visit your friend for two months but you have some sweets laced with high-fructose corn syrup and a soda every day. What happens? At the end of the two months, you have only a 50/50 chance of finding your friend’s house again. But if you didn’t indulge in the fructose-laden sweets you’ll have no problem finding it.

Wow.

That’s what we’re talking about here.

And now for the really interesting part of the experiment: the rats fed the high-DHA diet did as well as the water-only rats, suggesting that DHA might mitigate the damaging effects of fructose. Unfortunately, very few of us get enough DHA in our diets to make a difference.

But what about the genetic damage I mentioned?The study-runners already knew about the fructose/memory loss connection from the 2012 study, and that DHA seemed to mitigate it. They already knew the fructose-drinking rats had higher blood sugar, higher insulin levels, and higher triglycerides, suggesting that the high fructose corn syrup (HFCS) in our diets leads to diabetes. What they didn’t know was why. So they started sequencing genes.

They tested over 20,000 genes in the rats’ brains and what they found was downright scary. They found 700 genes in the hypothalamus (which controls metabolism) and 200 in the hippocampus (which controls memory—and is also the brain area first affected by Alzheimer’s) that were altered by the fructose. Even more importantly, most of these genes have a human counterpart. This nips the standard argument that “just because this happens in rats doesn’t mean it works that way in humans” in the bud.

The affected genes regulate—get this—metabolism, cell communication, and inflammation. Which implicates it–surprise!—in diabetes, heart disease, and Alzheimer’s. Earlier studies by the same researchers show that fructose damages communication between brain cells and increases toxic molecules in the brain, tying it even more strongly to Alzheimer’s. Other studies have shown a direct cause and effect relationship between obesity and insulin resistance and fructose consumption.

Big Food will ignore this study, but Big Pharma will embrace itWill this study have any effect on how much HFCS is added to our food? Of course not. It probably won’t even make it to the mainstream news. And if it does, you can bet that the seriousness of the results will be downplayed. Instead, we’ll be told that “we need more studies” and that HFCS really isn’t that different than table sugar—even though the rats were fed a dose of fructose that many of us easily match each day.We’ll be told that we should just cut down on added sugar all around. Which is good advice, but ignores the crystal-clear conclusion of the study—that added fructose makes us sick. That it actually changes our genes.

No, we won’t see a change in food manufacturing. But I’ll tell you what we are likely to see, thanks to this study and others like it that may follow. The researchers found that the genetic changes started with two particular genes. Once these genes were altered, the changes spread in a domino effect. So I’m willing to be that what we will see at some point is a new drug that targets these two genes. Instead of banning HFCS or being advised not to eat it, we’ll just be handed another pill.

Now, the fructose that occurs naturally in our foods isn’t likely to be a problem, the researchers say. The fructose in fruit is mitigated by other factors, and we simply can’t eat enough for it to cause damage anyway. It’s the added fructose we need to worry about. Which means we need to cut HFCS out of our diets once and for all.

So if you’re not already a label-reader, become one. If it has fructose or high-fructose corn syrup anywhere in the ingredient list, leave it on the shelf. And if it’s already in your pantry, throw it away.

If you’re drinking fruit juice as a “healthy” alternative to soft drinks, think again—not only does it have as much or more sugar than soft drinks, it also has an unnatural amount of fructose. And for God’s sake, if you care about your health, ditch the soda for water or unsweetened tea. It’s one of the best and easiest things you can do for your health, as this study so clearly shows.